Alrighty guys i got a toughy for you today. My brothers Sammy took a nasty turn for the worst a couple weeks ago. You can accelerate through the gears fine and it runs super fast when its still warming up but when you get it warmed up ( to the middle of the temp gauge) it will bog when you floor it. you can let off a little and it will go. Other times it will get to third and start bogging and when you let off it only lets you give it enough gas to sustain your speed which is about 35. We rebuilt the carb, and put in new fuel pump, fuel filter, fuel lines ( rubber) and cleaned out the hard lines with compressed air, new plugs, wires, distributor cap and coil. It will still have these same symptoms. Can anyone help?

O2 sensor maybe? Pcv valve stuck?

does it have an intake air divertor, like a summer winter position?  it sounds like it's sucking in  hot air
I'm not familiar with sammys, do the have temp controlled vacuum switches?

If it still has one, the catylitic (sp) converter may be plugged.

Big i think your right on on that one brother. we'll hack it tomarrow and see. Thanks guys we were at our wits end.

Interesting, my sidekick does that sometimes... hope you get it taken care of, it's a pain in the ass! I think the last time it did it to me was when I flushed all the fluids... I figure I dislodged some smudge somewhere and it was having trouble getting out of the system  

steveo